Kidney transplantation in patients with a prior heart transplant.

Background: Chronic kidney disease among prior heart transplant recipients is a growing problem that is likely to place an increased demand on a limited supply of kidney allografts. Allocation of the limited resource of kidneys for transplantation requires consideration of the demands of fair distribution and optimizing patient and graft survival. The aim of this study was to compare the kidney transplant outcomes among recipients of kidney after prior heart transplantation (KAH, n=456) with kidney transplantation in other clinical settings.

Methods: A retrospective cohort study using United Network for Organ Sharing registry data (1995-2008) was performed comparing renal allograft survival among KAH recipients with patients who underwent simultaneous kidney-heart transplant (SKH, n=252), primary kidney transplant alone (KA1, n=112,882), or repeat kidney transplant alone (KA2, n=14,070).

Results: The annual number of KAH recipients more than quadrupled during the study period from 24 in 1995 to 99 in 2008. In a multivariable analysis using Cox regression, allograft survival among KAH recipients was not different from SKH (P=0.16, hazards ratio [HR]=0.79, confidence interval [CI]=0.57-1.10), and KA2 (P=0.11, HR=0.86, CI=0.72-1.04), but it was inferior to KA1 (P<0.001, HR=0.66, CI=0.55-0.80). Patient death accounted for 75.2% of KAH kidney loss. Kidney quality as measured by living or deceased donors (P=0.62) and standard criteria or extended criteria (P=0.87) was not associated with survival; however, there was a trend toward improved survival (P=0.08) among recipients of a preemptive transplant.

Conclusion: Kidney graft survival among prior heart transplant recipients is inferior to KA1 but similar to other clinical scenarios. Preemptive transplantation with an extended criteria or living donor kidney should be encouraged.